Hesiod. Works and Days. (Lines 458-464).
So soon as the time for ploughing is proclaimed to men, then make haste, you and your slaves alike, in wet and in dry, to plough in the season for ploughing, and bestir yourself early in the morning so that your fields may be full. Plough in the spring; but fallow broken up in the summer will not belie your hopes. Sow fallow land when the soil is still getting light: fallow land is a defender from harm and a soother of children.